EP 0902932 A4 20010502 - ELECTRONIC ARTICLE SURVEILLANCE SYSTEM WITH CANCELLATION OF INTERFERENCE SIGNALS
Title (en)
ELECTRONIC ARTICLE SURVEILLANCE SYSTEM WITH CANCELLATION OF INTERFERENCE SIGNALS
Title (de)
ELEKTRONISCHES WARENÜBERWACHUNGSSYSTEM MIT STÖRSIGNALUNTERDRÜCKUNG
Title (fr)
SYSTEME DE SURVEILLANCE ELECTRONIQUE D'ARTICLES A SUPPRESSION DES SIGNAUX D'INTERFERENCE
Publication
Application
Priority
- US 9707959 W 19970509
- US 65694996 A 19960606
Abstract (en)
[origin: WO9746989A1] An electronic article surveillance system (100) includes a signal generator (22, 24, 26) for generating an interrogation signal (28) in an interrogation zone (30), an antenna (36) which receives a signal (34) present in the interrogation zone (30), and circuitry for cancelling interference. A hybrid interference component cancelling loop forms a digital interference estimate signal (108) which is converted (106) into an analog estimate signal, which is subtracted (102) from an input analog signal (40). The difference signal is digitized and subjected to additional digital interference cancellation processes (108). Each of the signal processing operations (108) entails performing a polyphase decomposition of a digital input signal, estimating a mean value of each of the resulting subsequences, and combining the estimated mean values to form an interference component estimate signal. An input sample window for a comb-filtering stage is phase adjusted relative to the interrogation signal to compensate for changes in phase of the marker signal (34).
IPC 1-7
IPC 8 full level
G08B 13/24 (2006.01)
CPC (source: EP US)
G08B 13/2471 (2013.01 - EP US); G08B 13/2488 (2013.01 - EP US)
Citation (search report)
- [A] EP 0565481 A1 19931013 - ACTRON ENTWICKLUNGS AG [CH]
- See references of WO 9746989A1
Designated contracting state (EPC)
DE ES FR GB SE
DOCDB simple family (publication)
WO 9746989 A1 19971211; WO 9746989 A9 20040318; AR 007520 A1 19991110; AU 3003397 A 19980105; AU 724342 B2 20000921; BR 9709659 A 19990810; CA 2249015 A1 19971211; CA 2249015 C 20040106; DE 69730026 D1 20040902; DE 69730026 T2 20050721; EP 0902932 A1 19990324; EP 0902932 A4 20010502; EP 0902932 B1 20040728; ES 2225971 T3 20050316; JP 2000511665 A 20000905; JP 3875997 B2 20070131; US 5699045 A 19971216
DOCDB simple family (application)
US 9707959 W 19970509; AR P970102479 A 19970606; AU 3003397 A 19970509; BR 9709659 A 19970509; CA 2249015 A 19970509; DE 69730026 T 19970509; EP 97924668 A 19970509; ES 97924668 T 19970509; JP 50058598 A 19970509; US 65694996 A 19960606